SC rough engagement & chirping
#1
Super Member
Thread Starter
SC rough engagement & chirping
This has become progressively worse over the last 2 months. The instant you get on the gas I hear a chirp & experience a brief rough patch in acceleration like the SC is hesitating. Reading suggests it's the SC clutch & maybe the belt/tensioners. What are my options in terms of replacing the clutch? Is this a good time to upgrade?
#2
Super Member
iTrader: (2)
perfect time especially when you find out how much an OEM clutch will cost you...I was going to do mine but then found out my clutch/pulley were replaced already by the original owner.... I would consider the fixed pulley but seems to be a mixed camp on who to get to tune and stability,,, my understanding is if you keep mods to a minimum like headers and the fixed pulley you should be good...
#3
Super Member
Thread Starter
I was on the FSP wagon but this is a daily driver for me & from reading a few online threads it appeared the FSP yields considerably worse fuel mileage so I would rather avoid that if possible.
I had intended the car to be lightly modified meaning ecu, cooling, headers and stock SC pulley. Sounds like an oem replacement will force me into an aftermarket option unless I hit a wrecker.
Are there any clutched pulleys that a stock ecu can manage?
I had intended the car to be lightly modified meaning ecu, cooling, headers and stock SC pulley. Sounds like an oem replacement will force me into an aftermarket option unless I hit a wrecker.
Are there any clutched pulleys that a stock ecu can manage?
#4
MBWorld Fanatic!
Somewhere there's a post of a guy running a fine-grit sandpaper in the gap between the pulley and the SC in order to clean debris out that may have marred the surface. I tried it on mine and there was a noticeable improvement, but only for a few days. At some point I'm going to take off the pulley and clean up both mating surfaces. I expect that will work well, even if it needs to be done periodically.
#5
MBWorld Fanatic!
If your car is high mileage like around 120k miles + you should look into taking the clutch off and getting it surface ground. Only take off the minimum amount to get it pretty flat about 0.1mm.
There are three 0.1mm shims behind the pulley your likely worn close to 0.1 already so once you machine 0.1mm your should be able to set it up to the WSM tolerance with one shim or maybe none.
With wear the clutch gets big grooves in it which bite/cut into the resin that protects the windings on the magnet. So its very beneficial to do this work and it will cost a fraction of what MB wants for a new pulley.
I have a sneaking suspicion these factory pulleys arent even flat on the mating surface from the factory (I have no proof of this because iv never seen a brand spankers one)
When I put a straight edge on my stock one I was rather surprised put it that way. Maybe they are designed like that but mines been fine ever since I had it surface ground.
There are three 0.1mm shims behind the pulley your likely worn close to 0.1 already so once you machine 0.1mm your should be able to set it up to the WSM tolerance with one shim or maybe none.
With wear the clutch gets big grooves in it which bite/cut into the resin that protects the windings on the magnet. So its very beneficial to do this work and it will cost a fraction of what MB wants for a new pulley.
I have a sneaking suspicion these factory pulleys arent even flat on the mating surface from the factory (I have no proof of this because iv never seen a brand spankers one)
When I put a straight edge on my stock one I was rather surprised put it that way. Maybe they are designed like that but mines been fine ever since I had it surface ground.
Last edited by austingtir; 11-03-2015 at 12:03 AM.
#6
Super Member
Thread Starter
Austingtir,
I am assuming a machine shop could do the grinding, has anyone else gone through that with good results?
Car has 125K miles
Where can i get shims? Any further links for reading about what you're proposing?
I am assuming a machine shop could do the grinding, has anyone else gone through that with good results?
Car has 125K miles
Where can i get shims? Any further links for reading about what you're proposing?
#7
MBWorld Fanatic!
You dont need any shims they are already behind the pulley now.
You are simply removing the shims to get the correct gap set on the clutch which is very important for the clutch to last. You use a feeler gauge to set the gap on the clutch this is why you need to remove the burrs otherwise its not done right.
You dont have to get it surface ground a competent machine shop should be able to use a lathe to spin it up and just remove the burrs/give it sand up.
Even some sandpaper down on some glass and some patience might get you to good enough. Or if you know how to use a good fine file to file something true that would likely work aswell just to remove the burrs.
Mines likely done about 10,000kms now and still no chirp.
You are simply removing the shims to get the correct gap set on the clutch which is very important for the clutch to last. You use a feeler gauge to set the gap on the clutch this is why you need to remove the burrs otherwise its not done right.
You dont have to get it surface ground a competent machine shop should be able to use a lathe to spin it up and just remove the burrs/give it sand up.
Even some sandpaper down on some glass and some patience might get you to good enough. Or if you know how to use a good fine file to file something true that would likely work aswell just to remove the burrs.
Mines likely done about 10,000kms now and still no chirp.
Last edited by austingtir; 11-03-2015 at 09:59 PM.
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#9
Super Member
Thread Starter
#10
MBWorld Fanatic!
I'll be running an EC Boxed tune. 80mm FSP and will run it without the resistor.
If I don't like it, EC will refund my money for the tune and I can sell the pulley. I'll only lose on labour costs....
Might as well try it
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